Synthesis of novel multi-site phase-transfer catalyst and its application in the reaction of 4,4′-bis(chloromethyl)-1,1′-biphenyl with 1-butanol

This work describes the etherification of 4,4′-bis(chloromethyl)-1,1′-biphenyl and 1-butanol catalyzed by a new multi-site phase-transfer catalyst as carried out in an alkaline solution/organic solvent two-phase medium. The new multi-site phase-transfer catalysts were obtained from the reaction of 4,4′-bis(chloromethyl)-1,1′-biphenyl and tertiary amines. During or after completing the reaction, the mono-substituted product (4,4′-(butoxymethyl)-1,1′-biphenyl) and di-substituted product (4,4′-bis(butoxymethyl)-1,1′-biphenyl) are both produced. A rational mechanism of the etherification was proposed based on the experimental observation and a kinetic model was developed. The two apparent rate constants of the organic-phase reactions were obtained via experimental data. The reaction is greatly enhanced by adding a small quantity of the new multi-site phase-transfer catalysts. This new novel phase-transfer catalyst exhibits higher reactivity than the “single-site” quaternary ammonium salts. Preliminary studies on the kinetics and the effect of various parameters such as agitation speed, amount of organic solvent, multi-site catalysts, potassium hydroxide, water, organic solvents, inorganic salt and temperature were investigated in detail. Rational explanations of the results are made.